pg atomic transaction test

transact.js

var pg = require('pg');

var client = new pg.Client('pg://user:[email protected]/postgres');
client.connect(function () {
  client.query('CREATE TEMP TABLE foo (bar real)', function () {
    for (var i = 0; i < 5; i++)
      insertRandomNumber();
  });
  client.once('drain', function () {
    client.query('SELECT bar FROM foo', function (err, results) {
      for (var i = 0; i < results.rowCount; i++)
        console.log(results.rows[i].bar);
    });
    client.once('drain', client.end.bind(client));
  });
});

function insertRandomNumber() {
  console.log('BEGIN');
  client.query('BEGIN', function () {
    console.log('INSERT');
    client.query('INSERT INTO foo VALUES (random()) RETURNING bar', function (err, result) {
      if (result.rows[0].bar < 0.5)
        console.log('COMMIT'), client.query('COMMIT');
      else
        console.log('ROLLBACK'), client.query('ROLLBACK');
    });
  });
}

Results in:

c:\node>node transact
BEGIN
BEGIN
BEGIN
BEGIN
BEGIN
INSERT
INSERT
INSERT
INSERT
INSERT
COMMIT
ROLLBACK
COMMIT
COMMIT
ROLLBACK
0.0732571
0.614192
0.43519
0.0143881
0.878153

c:\node>node transact
BEGIN
BEGIN
BEGIN
BEGIN
BEGIN
INSERT
INSERT
INSERT
INSERT
INSERT
ROLLBACK
COMMIT
COMMIT
ROLLBACK
ROLLBACK